Mars appears more Earth-like to us than most of the other planets because we can observe its surface, atmospheric clouds and hazes, and its brilliant white polar caps. The latter are composed of frozen CO2 and underlying water ice, and wax and wane during the Martian year. These aspects, along with the changing seasons and the possibility of life, have made Mars one of the most studied planets in our solar system.

The Red Planet Mars offers both casual and serious observers many challenges and delights, as well as providing astronomers a laboratory to study another planet's atmosphere and surface. Some Martian features even appear to shift position around the surface over extended periods of time.

With the advent of modern CCD camera technology the amateur can produce useful images of Mars when it is as small as 3.5 arcsec. Early in an apparition, Mars rises in the east or morning sky and sets with the rotation of the Earth in the western or evening sky. During the past few apparitions (2001-2018), observers began to take CCD images when Mars was only 30 degrees away from the Sun. Since Mars was only a visual magnitude of ~1.8 then the planet would have been difficult to locate bright twilight hours.

In the pre-apparition reports the observer will find the motion of Mars in our sky, the characteristics for that particular apparition, information pertaining to the polar cap(s) and any special events that may be seen during that particular apparition. As usual a calendar of events will be included with each report that contains cardinal dates for seasonal activity and orbital information of Mars.

MOTION OF MARS IN OUR SKY

As a general rule, an "apparition" begins when a planet emerges from the glare of the Sun shortly after conjunction. Mars will be in conjunction with the Sun on October 08, 2021 (109.7° Ls);however, it will not be safe to observeMars until after November 14, 2023 when it is at least12 degrees away from the glare of the Sun.

The apparent declination of Mars begins at -22.5° in early January 2022 the constellation Ophiuchusand will descend south into the constellation Sagittarius, on January 20th, into Capriconus on March 6th, then into Aquarius on April 12th, and Pisces on May 20th until July 10, 2022. After that Mars will be positioned within Ariesuntil August 10th when it moves into Taurus.Mars will be south of the celestial equator throughout the apparition until May 30, 2022 and begin climbing north of the celestial equator the next day.This is good news for those observing in the Northern Hemispheres because Mars will be seen high in their sky. Mars will be above the celestial equator until August 31, 2023.

By May 11, 2022, an ‘0.8’ visual magnitude Mars will be seen rising early in the morning sky in the constellation Aquariusand by August 27, 2022 will be at western quadrature with the phase defect or terminator of 45.7°.NOTE:The Solar Elongation for Mars is the angle between the lines of sight from Earth to the Sun and from Earth to Mars. When these lines of sight form a right triangle then Mars is at quadrature (eastern or western). For detailed definitions and graphics for the motion of Mars in our sky see these excellent web sites: Planetary Aspects and Elongations and Configurations.

Figure 1. A heliographic chart of the orbits of Mars and the Earth showing the relative positions of both planets. Quadrature is when Mars is directly east or west of Earth as shown.

The 2022-2023 apparition of Mars begins retrogression, or retrograde motion against the background stars eleven months after on October 30, 2022 (330° Ls) and continues through January 12, 2023 (8.2° Ls). Each night for this brief period of time; before, during and after opposition the Red Planet will appear to move backwards toward the western sky in theTaurus.Since the Martian year is about 687 Earth days long -- nearly twice as long as ours, the Martian seasons are similarly extended. While the Earth's seasons are nearly equal in duration, the Martian seasons can vary by as much as 52 days from each other due to that planet's greater orbital eccentricity (see Figure 2).

Figure 2. A heliographic chart of the orbits of Mars and the Earth showing the relative seasons of both planets in the planetocentric longitude system Ls. Graphic Ephemeris for the 2020 Perihelic Apparition of Mars. Original graph prepared by C.F. Capen and modified by J.D. Beish.

2022 APPARITION CHARACTERISTICS

Another general rule for predicting oppositions of Mars is from the following: the planet has an approximate 15.8-year periodic opposition cycle, which consists of three or four Aphelicoppositions and three consecutive Perihelicoppositions. Perihelic oppositions are also called "favorable" because the Earth and Mars come closest to each other on those occasions. We sometimes refer to this as the seven Martian synodic periods. This cycle is repeated every 79 years (± 4 to 5 days) and, if one were to live long enough, one would see this cycle nearly replicated in approximately 284 years. The 2022 Mars apparition is considered Transitional(between Aphelic and Perihelic) because the orbital longitude at opposition will be 79.3° from the aphelion longitude of 70° Ls and 99.7° Ls from perihelion (251° Ls).

NOTE: Ls is the planetocentric longitude of the Sun along the ecliptic of Mars' sky. 0° Ls is defined as that point where the Sun crosses the Martian celestial equator from south to north, that is the planet's northern hemisphere vernal equinox. The other Ls values that define the beginnings of Martian northern hemisphere seasons are: summer, 90° Ls; autumn, 180° Ls; and winter, 270° Ls. For Mars' southern hemisphere these values represent the opposite seasons. Distance (A.U.) - Distance from Earth to Mars in astronomical units, where one (1) A.U. equals 92,955,807.267 miles or 149,597,870.691 km.

Closest approachoccurs at 0218 UT on December 01, 2022 (347.1° Ls) with an apparent planetary disk diameter of 17.2'' at a distance of 0.54446547536492 astronomical units (AU) or 50,611,228 mi (81,450,876-km).During closest approach in 2022 the apparent diameter of Mars will be 5.4 arcsec smaller than it was at the same period in 2020; however, it will be 19 degrees higher in the sky – good for observing the Red Planet for observers in the northern and southern hemispheres of Earth. It should also be noted that closest approach between Earth and Mars is not necessarily coincident with the time of opposition but varies by as much as two weeks.

Oppositionoccurs 14 months after conjunction when Mars is on the opposite side of the Earth from the Sun. At that time, the two planets will lie nearly in a straight line with respect to the Sun, or five weeks after retrogression begins.Opposition will occur at 0459 UT on December 08, 2022 (350.7° Ls) with an apparent planetary disk diameter of 17.1 arcsec. Mars will remain visible for10 months after opposition and then become lost in the glare of the Sun around October 10, 2023; as it approaches the next conjunction (November 18, 2023). The cycle is complete in 780 Earth days.

Figure 3. A simulated view of the appearance of Mars during opposition at 0459 UT on December 08, 2022 (350.7° Ls, CM 240°)

The observable disk diameter of Mars will be greater than 6 arcsec from May 11, 2022 [-5.6°d] (225.0° Ls) and will not fall below this value until April 11, 2023 (49.3° Ls), lasting nearly 11 months or 184 degrees Ls. Imaging by CCD devices may begin with a disk diameter of 5 arcsec or more, commencing on or about March 18, 2020.

The Sub-Earth (De) and Sub-Solar (Ds) points are graphically represented in Figures 4 and 5. The 2022-2023 Ephemeris of Mars is tabulated on Internet in this web site. A glossary of Terms appears at the end of this table.

Figure 4. As it approaches Earth, it will swell from a small apparent disk of 6" in May 11, 2022 to a maximum diameter of 17.2” at closest approach on December 01, 2022, and then shrink as it moves away. Images shown at 0h UT.

Figure 5. Graphic Ephemeris of Mars during the2022-2023 apparition fromMay 11, 2022 through April 11, 2023. Opposition and 6 arcsec apparent diameter range are indicated. Plot illustrates the Declination (black line), the latitude of the Sub-Earth point (De) or the apparent tilt (green line) in areocentric degrees, and the latitude of the Sub-Solar point (brown line) in areocentric degrees. The areocentric longitude (Ls) of the Sun, shown along the bottom edge of the graph defines the Martian seasonal date. The value of Ls is 0° at the vernal equinox of the northern hemisphere, 70° when Mars is at aphelion, and 90° at the summer solstice of the northern hemisphere 251° when Mars is at perihelion, and 180° is northern autumn.

Figure 6. Graphic Ephemeris of Mars from May 11, 2022 through April 11, 2023. Plot illustrates the apparent diameter of Mars in seconds of arc. The areocentric longitude (Ls) of the Sun, shown along the bottom edge of the graph defines the Martian seasonal date.

THE NORTH AND SOUTH POLAR REGIONS

Astronomers will have a view of both polar regions during the next apparition. From the second week in May 2022 the Martian South Polar Region (SPR) will be positioned to be seen form the Earth and will remain so until February 08, 2023. Also, during the first week of September 2022 the North Polar Region (NPR) positioned to be seen form the Earth. For more detailed information on both polar regions click the north polar cap and south polar cap.

DUST STORMS

Observations of Mars indicate that dust storms occur around the time of northern summer solstice (90° - 105° Ls). However, accurate predictions are nearly impossible to make because of the complexities and unknown variables. When a great dust storm reaches maturity, Mars' disk appears bright orange and Mars' surface features are obscured.For more detailed information onMartian dust stormson this web site.